Rectal or vaginal administration of therapeutic doses of numerous pharmacological agents has been accomplished with numerous medicated devices. U.S. Pat. No. 4,237,888, for example, discloses a medicated device for administering rectally or vaginally to a female mammal a lipophilic prostaglandin in order to effect a discrete event in the mammalian reproductive cycle. Such device comprises three primary components, namely, a tampon-type support, a first polymer film affixed to the support and containing the drug, and a second polymer film laminated onto the first film to control the rate of release of the drug from the first film. Although this device has been adequate for its intended purposes, it has not proved satisfactory in all respects. In particular, the rate-controlling, second film was applied by a dipping process which did not provide a uniform film for controlling the release rate of the drug. Thus, the drug was dispensed at an unpredictable rate. The drug-bearing, first film is capable of releasing the drug at rates up to ten times faster than the rate permitted by the rate-controlling, second film.
Accordingly, it is an object of the present invention to provide a medicated drug-delivery device for supporting a sheet comprising a drug-bearing film or membrane and a rate-controlling film or membrane in which a constant surface area of the rate-controlling film is exposed to vaginal or rectal fluid and no edge portions of the drug-bearing film are exposed to such fluid.